19-3169; Rev 0; 1/04 MAX1538 Evaluation Kit The MAX1538 evaluation kit (EV kit) is a fully assembled and tested surface-mount circuit board that routes charge and discharge currents between two battery packs, a battery charger, and an AC-adapter power source. The circuit uses a MAX1538 IC in a 28-pin thin QFN package and is configured for a 4.75VDC to 28VDC AC-adapter input range. The EV kit uses eight P-channel MOSFETs to steer current between the power sources and the load. The battery minimum voltage level sets the threshold for battery undervoltage conditions and can be adjusted from 4.65V to 13.0V. Features ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ 4.75V to 28V AC-Adapter Input Range Up to 10A Steering Capability P-Channel MOSFET Steering Switches Adjustable Battery Minimum Voltage Level Adjustable Airline/AC-Adapter Detection Voltages Manual-or Computer-Controlled Interface On-Board Status LEDs Surface-Mount Components Fully Assembled and Tested Ordering Information PART TEMP RANGE MAX1538EVKIT 0°C to +70°C IC PACKAGE 28 Thin QFN Component List DESIGNATION QTY DESCRIPTION C1 1 1.0µF ±20%, 10V X5R ceramic capacitor (0603) TDK C1608X5R1A105M C2 1 Not installed (2220) C3 1 Not installed (D-case) 3 47µF, 35V low-ESR tantalum capacitors (E-case) AVX TPSE476M035R0250 or AVX TPSE476M035R0200 2 0.1µF ±20%, 50V X7R ceramic capacitors (0603) TDK C1608X7R1H104M C4, C5, C6 C7, C11 C8, C9 C10 C12, C13 C14 D1 D2, D3, D4 J1 DESIGNATION QTY JU1–JU5 DESCRIPTION 5 Not installed (SIP-2) N1–N3 3 Digital logic N-channel MOSFETs (SOT23) Central Semiconductor 2N7002 Top mark = 702 P1–P8 8 30V P-channel MOSFETs (8-pin SO) Fairchild FDS6679 R1 1 100kΩ ±5% resistor (0402) R2, R3 2 10kΩ potentiometers, 12-turn, 1/4in R4, R5, R6 3 330kΩ ±5% resistors (0402) R7 1 10mΩ ±2%, reverse-geometry sense resistor (1225) IRC LRC-LRF1225-01-R010-F R8, R9, R14 3 620Ω ±5% resistors (1206) 2 0.1µF ±20%, 10V X5R ceramic capacitors (0402) TDK C1005X5R1A104M R10–R13 4 160kΩ ±5% resistors (0402) 1 4.7µF ±20%, 6.3V X5R ceramic capacitor (0805) TDK C2012X5R0J475M R15, R16 2 500kΩ potentiometers, 12-turn, 1/4in R17, R18 2 Not installed (2010) Not installed (0805) SW1–SW3 3 3-position, SPDT, slide switches 4 2-circuit terminal blocks 1 1.0µF, 50V X7R ceramic capacitor (1206) TDK C3216X7R1H105M TB1–TB4 TP1–TP12 12 Test points U1 1 Maxim MAX1538ETI (28-pin QFN) 1 Dual diode (SOT23) Central Semiconductor CMPD3003C Top mark = LLC U2 1 Maxim MAX1615EUK (5-pin SOT23) Top mark = ABZD U3, U4 2 Maxim MAX6817EUT (6-pin SOT23) Top mark = AAAU None 1 MAX1538 EV Kit PC board 0 3 Green surface-mount LEDs (SS) Panasonic LNJ308G8LRA 1 Dual-row, 16-pin header ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 Evaluates: MAX1538 General Description Evaluates: MAX1538 MAX1538 Evaluation Kit Component Suppliers SUPPLIER PHONE FAX WEBSITE AVX 843-946-0238 843-626-3123 www.avxcorp.com Central Semiconductor 631-435-1110 631-435-1824 www.centralsemi.com Fairchild 888-522-5372 — www.fairchildsemi.com IRC 361-992-7900 361-992-3377 www.irctt.com Panasonic 714-373-7366 714-737-7323 www.panasonic.com TDK 847-803-6100 847-390-4405 www.component.tdk.com Note: Please indicate that you are using the MAX1538 when contacting these component suppliers. Quick Start Recommended Equipment • Two 16.8VDC Li+ battery packs • One variable 16.8V, 1A current-limited DC source to emulate a battery charger • One variable 20V, 10A DC source to emulate an AC adapter • One 10A, 300W electronic load Procedure The MAX1538 EV kit is fully assembled and tested. Follow the steps below to verify board operation. Do not turn on the power supply until all connections are completed: 1) Ensure that SW1 is in the down position (charge mode OFF). 2) Ensure that SW2 is in the down position (relearn mode OFF). 3) Ensure that SW3 is in the down position (battery A selected). 4) Set the DC power supply (used to emulate the battery charger) to 16.8V. 5) Set the DC power supply (used to emulate the AC adapter) to 20V. 6) Ensure that all DC power supplies are turned off. 7) Connect the first battery to the BATA and GND pads. 8) Connect the second battery to the BATB and GND pads. 2 9) Connect the AC-adapter power supply to the ADPIN and GND pads. 10) Connect the electronic load to the EXTLD and GND pads. Note: Terminal blocks TB1–TB4 can be used instead of the pads for power-supply connections in steps 8–11. 11) Connect the positive terminal of the battery-charger power supply to the CHGIN pad. Connect the negative terminal of the battery-charger power supply to the GND pad (located by the BATB terminal block). 12) Turn on the AC-adapter power supply. 13) Turn on the battery-charger power supply. 14) Set the electronic load to draw 5A. 15) Enable the electronic load. 16) Verify that LED D3 is lit and that LEDs D2 and D4 are not lit (AC adapter present). Detailed Description The MAX1538 EV kit circuit routes charge and discharge currents between two battery packs, a battery charger, and an AC adapter or DC power source. The circuit uses a MAX1538 in a 28-pin thin QFN package to control eight steering P-channel MOSFET switches. Monitor the MOSFET control signals at test-points TP1–TP8. A MAX1615 low-power linear regulator provides the circuit board’s 3.3V power for logic ICs and status LEDs. The EV kit’s AC-adapter input (ADPIN) range is from 4.75VDC to 28VDC. Figure 1 depicts a typical setup with batteries and battery charger connected to the EV kit. _______________________________________________________________________________________ MAX1538 Evaluation Kit TB2 GND ADPIN BATA TB1 (DC SUPPLY) BATTERY A MAX1538 EV KIT To set the AC adapter trip threshold, apply the minimum AC adapter voltage to the ADPIN pad and measure the voltage at TP11. Adjust potentiometer R2 until the TP11 voltage measures 2.0V. A clockwise turn on either potentiometer increases the measured voltage, while a counterclockwise turn on the potentiometer decreases the measured voltage. CHGIN GND Battery Charging RSNS+ RSNSEXTLD GND TB4 GND GND BATB TB3 Charge the selected battery (see the Battery Selection section) by moving the CHRG switch (SW1) to the up position. Disable the charging path by moving the switch to the down position. BATTERY B SYSTEM Battery Relearning The MAX1538 features battery relearning. Moving the RELRN switch (SW2) to the up position, places the MAX1538 into relearn mode. Moving the RELRN switch to the down position, places the MAX1538 into normal mode. CURRENT SENSE Battery Selection (DC SUPPLY) INPUT OUTPUT BATTERY CHARGER Figure 1. MAX1538 EV Kit Connection Diagram Potentiometers (R15, R16) allow easy adjustment of the minimum battery voltage threshold. Below this threshold, the battery is considered undervoltage and is not selected. See the Battery-Minimum Voltage Level Adjustment section for more information on adjusting the level. LEDs indicate the status of the AC adapter and batteries. The LEDs are driven by N-channel logic FETs. Jumpers are provided to disable the switches, CMOS switch debouncers, and LEDs used for evaluating power usage. Setting the Adapter Trip Thresholds The MAX1538 EV kit allows for adjustable AC adapter and airline adapter trip thresholds. The airline adapter trip threshold must be set before the AC adapter trip threshold. Adjusting the BATSEL switch (SW3) selects from which battery the EV kit powers the load. If the switch is in the up position, battery B powers the load. If the switch is in the down position, battery A powers the load. If the selected battery is not present or undervoltage, that battery is not connected to the load. Battery Minimum Voltage-Level Adjustment Adjusting potentiometers R16 and R15, set the minimum A and B battery voltages, respectively. Turning the potentiometer clockwise increases the minimum battery voltage. Turning the potentiometer counterclockwise decreases the minimum battery voltage. To adjust the minimum battery voltage to a predetermined value, monitor the voltage at TP10/TP9 (battery A/B). Turn the respective potentiometer until the measured voltage is equal to 1/5 the desired minimum battery voltage. The MAX1538 EV kit allows for minimum battery thresholds between 4.65V and 13.0V. _______________________________________________________________________________________ 3 Evaluates: MAX1538 To set the airline adapter trip threshold, apply the minimum airline adapter voltage to the ADPIN pad and measure the voltage at TP12. Adjust potentiometer R3 until the TP12 voltage measures 2.0V. Evaluates: MAX1538 MAX1538 Evaluation Kit Output Indicators Using the Optional Parallel Interface The MAX1538 EV kit features LEDs that indicate the status of the MAX1538 output lines. A lit LED indicates an output state of 1, while an unlit LED indicates an output state of zero. Use Table 1 to decode the LED status. The MAX1538 EV kit features an additional header (J1) that can be connected to a user-provided computer interface. When using this interface, disable the manual interface (switches and LEDs) by cutting the traces at jumpers JU3, JU4, and JU5. Also disable the on-board MAX1615 power supply by cutting the traces at jumpers JU1 and JU2. See Table 2 for header pin connections. Table 1. Output Indicator Status OUTPUT Reducing the Solution STATE OUT2 (D4) OUT1 (D3) OUT0 (D2) 0 0 0 Battery A 0 0 1 Battery B 0 1 0 AC adapter 0 1 1 Airline adapter 1 0 0 Battery A 1 0 1 Battery B 1 1 0 Battery A 1 1 1 Battery B SOURCE DESCRIPTION Eight MOSFETs are not required if the application does not use specific features of the MAX1538. MOSFET P1, P4, or both, may be removed depending on what features are required. Relearning Mode Disabled Supplying EXTLD If the relearning mode of the MAX1538 is not required, remove MOSFET P1 and short the pads of resistor R17. Relearning mode supplying EXTLD When using a buck-converter battery charger (i.e., the AC-adapter voltage is greater than the charge voltage of the charger), remove MOSFET P4 and short the pads of resistor R18. Buck Charger Charging Table 2. External Controller Connections MAX1538 PIN CONNECTIONS HOSTVCC* OUT0 OUT1 OUT2 CHRG RELRN BATSEL GND J1-1 J1-7 J1-5 J1-3 J1-9 J1-11 J1-13 J1-15** *The host must be able to supply a minimum of 3.3V at 1 mA. **In addition to J1–15, all even-numbered pins from J1-2 to J1-16 are GND. 4 _______________________________________________________________________________________ MAX1538 Evaluation Kit Evaluates: MAX1538 ADPIN R1 100kΩ TP1 TP12 10 HOSTVCC HOSTVCC 3 R3 10kΩ 3 R2 10kΩ 1 12 11 9 2 AIRDET ADPIN ADPPWR 4 12 TB1-2 56 TB1 RSNS+ 78 TP11 GND R7 10mΩ 2% 2 R5 330kΩ TB1-1 R17 OPEN P1 ACDET GND R4 330kΩ C14 1µF 3 78 R6 330kΩ OUT0 RSNSC2 OPEN 56 TP2 6 OUT1 7 OUT2 8 CHRG 5 RELRN 4 BATSEL 3 21 15 OUT0 REVBLK OUT1 EXTLD ADPBLK OUT2 P2 4 13 EXTLD 3 16 TP3 14 12 EXTLD 12 C4 47µF 35V 3 4 C5 47µF 35V C6 47µF 35V P3 28 C1 1.0µF 27 R12 160kΩ GND 56 78 78 56 TP4 BATSEL N.C. U1 DISBAT 18 R18 OPEN P4 4 3 12 12 3 N.C. VDD BATA GND DISA BATA 25 2 BATA CHGA 56 78 78 56 19 3 1 1 MINVA CHGIN GND CHGIN TP7 CHGB 21 17 12 TP10 R11 160kΩ TB2 P6 4 3 2 TB2-1 TB2-2 TP6 TP9 R13 160kΩ R15 500kΩ C19 OPEN MINVB 1 R10 160kΩ C12 OPEN 4 24 TP5 3 2 TB4 RELRN P5 R16 500kΩ TB4-2 CHRG MAX1538 VDD TB4-1 20 C3 OPEN 3 4 P7 GND HOSTVCC J1 VCC JU2 J1-2 J1-1 J1-4 J1-3 OUT2 J1-6 J1-5 OUT1 J1-8 J1-7 OUT0 J1-10 J1-9 CHRG J1-12 J1-11 RELRN J1-14 J1-13 BATSEL J1-16 J1-15 CUT HERE 56 78 78 56 TB3-2 TP8 DISB BATB 23 22 TB3 P8 4 3 TB3-1 BATB 12 C13 OPEN BATSUP D1 R20 OPEN 1 3 26 C11 0.1µF 2 BATA Figure 2. MAX1538 EV Kit Schematic (Sheet 1 of 2) _______________________________________________________________________________________ 5 Evaluates: MAX1538 MAX1538 Evaluation Kit VCC EXTLD JU1 CUT HERE 5 1 SHDN IN C7 0.1µF C8 0.1µF 2 1 5 U2 1 IN1 3 MAX1615 GND 1 5/3 (FB) OUT C10 4.7µF 6 JU3 CUT HERE OUT1 U3 4 JU4 CUT HERE 6 JU5 CUT HERE CHRG MAX6817 VCC 3 SW1 2 VCC 4 SW2 2 3 IN2 OUT2 RELRN 3 GND 2 VCC C9 0.1µF 5 VCC VCC D2 VCC D3 1 D4 SW3 2 VCC 1 IN1 3 U4 OUT1 MAX6817 R8 620Ω R9 620Ω 3 N1 2 R14 620Ω 3 1 N2 OUT0 2 3 3 1 N3 OUT1 2 IN2 OUT2 4 GND 1 OUT2 2 Figure 2. MAX1538 EV Kit Schematic (Sheet 2 of 2) 6 _______________________________________________________________________________________ BATSEL MAX1538 Evaluation Kit Evaluates: MAX1538 Figure 3. MAX1538 EV Kit Component Placement Guide—Component Side _______________________________________________________________________________________ 7 Evaluates: MAX1538 MAX1538 Evaluation Kit Figure 4. MAX1538 EV Kit PC Board Layout—Component Side 8 _______________________________________________________________________________________ MAX1538 Evaluation Kit Evaluates: MAX1538 Figure 5. MAX1538 EV Kit PC Board Layout—Solder Side Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 9 © 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.